Transient myocardial ischemia is a manifestation of coronary heart disease. In recent years, episodes of silent (i.e., nonpainful) ischemia have been observed in the context of relatively low heart rates, suggesting mediation by acute coronary vasoconstriction rather than increased myocardial demand. The present project addresses the question of whether such episodes are triggered by specific behavioral interactions. A program has been developed for a portable computer which enables patients to regularly record behavioral interactions during periods of cardiac monitoring with a minimum of intrusion into daily activities. Identification of specific behavioral antecedents of episodes of transient myocardial ischemia could lead to the development of nonpharmacological interventions for their prevention.